Telephone-transmitter



(No Model.)

W. 1-1. COLLINS.

TELEPHONE TRANSMITTER. 110.391,356. Patented Oct. 16, 1888.

'ilnrrne STATES PATENT i trice.

WILLIAM H. COLLINS, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JACOB KIRKNER, OF NEW YORK, N. Y., AND ROBERT BINES, OF CHICAGO,

ILLINOIS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 391,356, dated October 16, 1888.

Application tled April 20, 1887. Serial No. 235,566. (No model.)

To all whom, it may concern.-

Beit known that I, WILLIAM H. CoLLINs, a citizen of the United States, and residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone-Transmitters, which is fully set forth in the following specification, reference being had to the accompanying drawings, in which- Figure l is a sectional view of a telephonetransmitter embodying my invention; Fig. 2, a similar view of a modified form of transmitter; Fig. 3, a similar view of another modification; Fig. 4, a detail face view'of one of the electrodes enlarged; Fig. 5, a similar view o'f a modified form of the same; and Fig. 6 a detail sectional view taken on the line 1 l of Fig. 4. l

Like letters refer to like parts in all the Iigures oi the drawings.

My invention relates to telephone-transmitters, and is in the nature of an improvement upon the apparatus for which Letters Patent ofthe United States No. 352,119 were granted 23 to me November 9, 1886.

My present invention has for its object to provide a construction whereby the variations of the current shall be reduced to a minimum at all points in the circuit of the instrument,

3o except at the point where such variations are designed to be produced, to wit, between the contact-surfaces of the electrodes.

To this end my presentinvention consists in certain novel features,which I will now pro- 35 ceed to describe, and will then particularly point out in the claims.

In the drawings I have shown my invention carried out in several different ways.

Referring now more .particularly to Fig.

4o l, A indicates the vibratory diaphragm clamped firmly in the cell a at its margin and carrying the electrode B, constructed in the manner hereinafter described, and secured to the diaphragm A by means of a screw, b, or

any other` suitable device for the purpose. C represents a bracket secured to the cell a and constructed, preferably, of hard rubber or other non-conducting material. rIhis bracket carries the electrode-support D,which is a yielding support, preferably constructed of one of the softer metals, for the purpose hereinafter described. The support D isattached directly to the bracket C at one end, its other end being attached to a tension-screw, (l, passing through an arm of the bracket Cand provided with an adjusting-nut, d', above and a locknut, d2, below the same. On the support D is mounted a pin, E, extending upward and entering a suitable socket in the rear electrode, F. This socket may be formed directly in the electrode itself; but I prefer to employ a separate socket piece or bushing, e, screwed into or otherwise secured to the electrede and provided with a conical recess to receive the correspondingly-shaped end of the pin E. The electrode F is provided at the top with a recess, f, to receive a downwardlyextending pin, G, attached to the support D. The recessf contains a lling, H, of mercury, and the walls of the recess and end of the pin are amalgamated or made susceptible of amalgamation before the mercury is placed in position. The` electrodes are preferably constructed of carbon and plated or otherwise covered with a coating, h, of metal, such as copper. The adjacent faces of the electrodes are provided with grooves h', formed therein and arranged in any suitable manner, two different arrangements being shown, one in Fig. 4 and another in Fig. 5. The meeting faces ofthe electrodes are polished to as high a degrec of smoothness as possible, the metallic plating being either omitted from these surfaces while the operation of plating is being performed or removed therefrom during the grinding and polishing of the said surfaces. I represents a screw passing through the bracket C and arranged to bear against the yielding support D to form an adjustable stop to limit its Vibrations.

In the construction shown in Fig. 2 the bracket C carries an arc-shaped supportingframe, C', to which the yielding support D is attached in the manner shown and already described in relation to Fig. l. The screw I passes through the cord-piece c' of the arcshaped `frame C in the manner shown.

In theconstruction showninFig-3thebrackct C has a bearing and s et screw, C, to receive the shankjof an arc-shaped supporting-frame, J. From the lower arm fof this frame the pin E extends upward to support the electrode F, while from the upper arm a spring-piece, K, extends downward and enters the recess f, which in this case is preferably inclined to accommodate the correspondingly inclined spring-piece. The recessfhas a filling, II, of mercury, and the spring-piece K is preferably provided with a ball or enlargement, 7c, on its end within the recess f, to enable it to better support the electrode. The spring-piece K is attached to a screw, K', passing through a suitably-threaded aperture in the frame J, and provided with a locking-nut, 7c. The entire frame .I may be adj usted toward or from the diaphragm to bring the electrodes into proper relative position, and the rear electrode may be independently adjusted by means of the screw K in an obvious manner.

The operation of my improved transmitter is so far as its general features are concerned the same as that of the apparatus set forth in my prior Letters Patent, hereinbefore referred to. The yielding support is, as hereinbefore stated, constructed of one of the softer metals, and is held at a loose tension, so that it acts but sluggishly in returning to its normal position. It forms a cushion or support for holding the rear electrode lightly in contact with the diaphragm-electrode when the diaphragm is not in motion. It serves to make the instrument sensitiveto the slightest atmospheric vibrations and at the same time capable of transmitting the loudest sounds distinctly.

The electrodes are grooved, as hereinbefore described, in order to allow the air to pass freely between them, and thus prevent the accumulation of moisture between them, which moisture, beinga conductor of electrici ty, would by its presence affect the operation of the instrument. These grooves also serve another purpose in conjunction with the metallic plating hereinbefore described. This plating is v applied to the whole surface of each electrode,

including the surface of the recess f, which receives the mercury, the contact-surfaces of the electrodes being afterward cleaned and polished, thus removing the plating from the said surfaces, but not from the grooves therein. The metallic plating within 'the recess f is moistened with acid, or otherwise Vmade susceptible of amalgamation before the mercury H is placed therein, and the end ofthe pin G is similarly treated or separately amalgamated in any known manner. When the parts are in position, the mercury within the recess serves to produce an intimate electrical connection between the electrode and the pin G, and this effect is increased by the amalgamation of the walls of the recess and the end of the pin, the object being to allow the current to more readily pass from the metallic plating of the electrode, by means of the amalgamated surface thereof within the recess, to the mercury, and from the mercury to the amalgamated end of the pin G, and thence to the body portion of the pin and to its support D. By reason of this construction the resistance to the passage of the current is reduced to a minimum between the electrode and its support, since it does not have to pass abruptly from one conductor to another of a different nature merely in mechanical contact with the rst,and all breaks and variations between the rear electrode and its support are prevented, while at the same time the electrode is not rigidly connected to the said support. o f the plating in the grooves h serves to conduct the current more readily to the main body of the plating and through thesaid plating to the mercury filling Hin the recessf. This resultsfrom the fact that if the carbon contactsurfaces of the electrodes are only in contact at some one point distant from the plating the current would have to pass through the carbon body a considerable distance, whereas by following the carbon until it reaches one of these grooves it will follow the plating of metal therein, and thus be enabled to pass through a good conductor instead of passing through the poorer conductor furnished by the carbon body of the electrode. Indeed, the object of the plating of metal is chiefly to provide a' good conductor for the current, and thus reduce the resistance, while at the same time the beneficial results of carbon contact-surfaces are retained.

It is obvious that various modifications may be made without departing from the principle of my invention, and I therefore do not wish to be understood as limiting myself strictly to the precise details hereinbefore deseribed,and shown in the drawings.

Having thus described myinvention, what I claim as new, and desire to secure by Letters Patent, is

1. In a telephone-transmitter, the vibratory diaphragm and its electrode, in combination with a second electrode provided with a mercuryfllled recess, and a yielding support carrying said second electrode and provided with a pin extending into the mercury, substantially as and for the purposes specified.

2. In a telephone-transmitter, the vibratory diaphragm and its electrode, in combination with a second electrode, and a yielding support carrying said second electrode, and provided with a pin extending into a mercuryfilled recess in the same, the end of the pin and the walls of the recess being amalgamated, substantially as and for the purposes specified.

3. In a telephone-transmitter, the electrodes constructed of carbon and provided with a plating of copper or other conducting material, except upon their contact-surfaces, substantially as and for the purposes specified.

' 4. In a telephone-transmitter, the electrodes constructed of carbon, and having the grooves in their contact-surfaces, said electrodes being provided with a plating of copper or other conducting metal extending through the said grooves and over the body of each electrode,

That portion IOC IIO

except the contact-surfaces thereof, substantially as and for the purposes specied.

5. In a telephone-transmitter, the carbon electrode F, provided with arecess, f, and having aplating, 7L, of copper or other conducting metal, extending into the said recess, in combination with a filling, H, of mercury within the said recess and amalgamated with the plating therein, and a yielding support carrying the said electrode, and provided with a pin, G, immersed in the mercury in the recess and having its immersed end amalgarnated, substantially as and for the purposes specified.

6. In a telephone-transmitter, the vibratory diaphragm and its electrode, in combination with ayielding supportprovided with upwardly and downwardly extending pins, and a second electrode provided with recesses at top and bottom to receive the said pins, substantially as and for the purposes specified.

7. In a telephone-transmitter, the vibratory diaphragm and its electrode, in combination with a yielding support provided with up wardly and downwardly extending pins, and a second electrode provided with a socket to receive the former pin and a mercury-filled recess to receive the latter, substantially as and for the purposes specified.

8. In a telephone-transmitter, the cell and the vibratory diaphragm and its electrode carried thereby, in combination with the bracket C, rigidly attached to the cell, the yielding support D, carrying a second electrode, and having one end attached to one arm of the bracket and the other end connected to a tension-screw passing through the other arm of' the bracket, substantially as and for the purposes specified.

9. In atelephonetransmitter, the cell a and the vibratory diaphragm A and its electrode B, in combination with the bracket G, rigidly attached to the cell, the yielding support D, of adjustable tension, carrying the second elcctrode, F, and mounted on the bracket C, and the stop-screw I, extending through the vertical arm of the bracket in the rear of' the yielding support on a line with the electrode carried thereby and adjustable in the said bracket to limit the motion of the electrode and its support, substantially as and for the purposes specified.

VILLIAM H. COLLINS.

Vitnesses:

IRVINE MILLER, C. FEIGEL. 

